The present invention relates to a new and improved construction of a vacuum switch of the type incorporating two contact elements arranged in an evacuated housing, the contact elements being in contact with one another when the switch is closed and can be disconnected from one another for the purpose of cutting-off the current, and wherein at least one of the contact elements is movable in one direction.
At the present time there are designed vacuum switches for rated cut-off current intensities up to 50 kA and greater. Such cut-off current intensities correspond to asymmetrical cut-in current intensities exceeding 100 kA (peak value). Additionally, the external dimensions of the switch are increasingly becoming smaller in order to reduce the distance between the phases. This development has as a consequence thereof that the electrodynamic forces, which are exerted by the current-carrying components upon one another, always become greater, so that the danger exists that the mechanical strength of the current-carrying components, normally fabricated of copper, is no longer sufficient to prevent permanent deformation thereof. This is especially so with respect to the contact elements, particularly the movable contact elements.